The invention concerns a cooling body for cooling power gates.
The cooling of power gates by means of cooling bodies in the form of so-called cooling rails is known. The cooling agent flows in longitudinal direction through the cooling ducts and thus removes the heat due to energy losses from power gates mounted to the outside of the cooling body. Since the characteristic data for the components depend strongly on the temperature, the aim is not to exceed a maximum temperature gradient of 5 K in longitudinal direction on the cooling surface.
The Patent DE-C-39 08 996 discloses a ceramic cooling body with a plurality of cooling ducts inside the cooling body, wherein the flow through neighboring cooling ducts inside the cooling body is in part parallel and in part antiparallel. The disadvantage of the arrangements is that the heat removal is insufficient. A large temperature gradient forms along the flow direction. The components to be cooled are not on the same temperature level.
WO-A-95/17765 discloses an arrangement where a cooling pipe is pressed into a cooling body in such a way that cross-sectional constrictions develop in the cooling pipe. The disadvantage here is that the flow resistance is increased strongly and the flow does not stall reliably at the constrictions, but can continue to flow laminar. Furthermore, the transition from the cooling body to the pressed-in cooling pipe constitutes an undesired heat resistance, which worsens the cooling.
A cooling rail that is open on both sides is known from DE-A-44 01 607, where a partition with regularly spaced boreholes is placed on the inside of the cooling duct, parallel to the flow direction. The inside of the cooling rail is thereby separated into two cooling ducts. Swirling and flow stall bodies are additionally inserted into each of the two cooling ducts, in order to homogenize and improve the cooling along the duct through the turbulence generated in the cooling agent. However, this measure leads to a drastic increase in the flow resistance in the cooling duct, which cannot be tolerated with the standard high flow speeds in cooling bodies for power gates. The heat resistance between the inserted partition and/or the inserted swirling bodies and the cooling rail furthermore cannot be neglected, so that the partition and the inserts as such hardly contribute to the heat removal.
Cooling bodies for power gates are frequently operated with flow speeds and pressure differences for the cooling agent in the cooling duct that are at the upper performance limit for the cooling body with respect to flow and heat removal.